Wimpole Victorian Gardens - Autumn work (Photo: Rob Renfree)
REDUCING LIMESCALE DEPOSITS some practical results by Roger Jayes.

If you live in hard water areas you'll have noticed the white limescale deposits around taps, in the bath and on washing up.
The lime arrives in the water, but it has an unfortunate habit of adhering to things rather than disappearing down the plughole, in particular around hot taps. Not only does it look unsightly, it also scales up kettles, and more hidden areas such as the inside of your hot water tank and pipes. This leads to in-efficient use of electricity, and the need to use more chemical cleaners to remove it. And that's really not good for the environment.
It was this thought that prompted me to investigate further (well also the real fact I hate cleaning!!).
If you're wondering at this point is it worth reading the article further, well yes I did come up with a solution (no pun intended!!) that worked for under £30 and costs around 4p a week to run.
I've tried not to be too technical with explanations, but have included links to none commercial technical commentry for those so inclined.

So can we do reduce limescale and be environmentally friendly, here are some options:

option 1) stick to chemical cleaners and scrubbing. Well yes you can. On the plus side it exercises the arm muscles but on the down side it's time consuming and those chemicals are not to friendly for the environment plus they cost money. You'd always have to put up with some amount of limescale deposits particularly on the shower door glass!

option 2) buy a water softener - the initial cost can be high, the softener uses electricity for the softening process, it has to be plumbed in and needs salt adding regularly. I estimated the cost to be upwards of £500 depending on how much or how less work you can do yourself. You should also ensure at least one tap in the house has access to the none softened water for drinking. You can find more information on the UK government DWI website.
Having used a water softener in a previous house, I decided I'd like to find a simpler, more elegant solution.

option 3) use an electronic descaler - now, if you've already been off to the DWI website and returned here, you may have spotted their advice on such things (which they call Magnetic and Electronic conditioning devices)...here's what they say:

"Some of these devices have been shown to be effective in reducing the amount of fur or scale that actually sticks to pipes or heating elements. They do not soften water. However, not all products on the market give satisfactory performance. You are advised not to buy one of these devices unless the supplier will agree to a sale or return, subject to satisfactory performance."

Doesn't sound too encouraging, and realistically how do you actually define "satisfactory performance", more to the point try and get your money back? Being electonically minded, I decided to investigate further, but to steer clear of commercial websites and look at more serious scientifically based data.

One very technical article on magnetic devices hinted the process could be credible (in my case the magnetic device was in fact the electronic circuit producing the magnetic field via a coiled wire).

Another article suggested that mains powered electro-magnetic devices were suitable for whole house treatment.

Basically, these devices consist of an electronic circuit which produces an alternating frequency signal of typically a few kilohertz. This drives an amplifier which in turn feeds a coil of wire around the incoming water pipe. The current flowing in the coil of wire produces a magnetic field through which the water passes, and in doing so the electrical properties of the lime particles are modified in such a way to reduce the amount of limescale formed (ie reduce their ability to stick to your taps, pipes etc.)
But lets be clear, the lime remains in the water, but exits harmlessly down the plughole, unlike water softeners which filter out the limescale.

Looking at the commercial sites, some electronic descalers are microprocessor controlled, some have two coils, some are "higher power". Many other commercial "reasons" are given to explain why one device is better than a competitors. They all seem to be upwards of £100 and some heading to £300. One even offered different models for different size houses (the bigger the house the higher the price), but frankly I could not see any scientific justification for this. I did get a bit cynical after a while with the claims!! and spending a few hundred pounds on something that may not work wasn't my idea of shrewd spending. A search for a circuit diagram on the internet had no success either.

However I came across a kit from a UK company called Magenta Electronics.
This kit is in fact from an article in October 1997 EPE (Everyday Practical Electronics) magazine.
If you can get hold of the magazine, it has all the details and the PIC software download is on the EPE site.
The circuit itself is simple and I estimated the cost of parts is no more than £10 if you chose to build it from scratch.
As the kit was only £22.95, I decided to buy one. You will also need to buy the mains power supply for the kit which is another £3.99 from Magenta, though I have seen suitable alternatives for around £1.50 - £2.00 available from other component suppliers. Fortunately I have a number of these lying around and one that suited - so £3.99 saved and an old power supply usefully recycled!!
The kit does require soldering skills and ability to recognise electronic components and values but is otherwise complete and easy to follow and does contain guidance on component identification.

The kit arrived, and took around 2 hours to assemble and check out. All appeared well and the red/green indicator LED told me the circuit was working as expected, so I fitted it into the neat little black box supplied with the kit and started the process of installation. The coil consists of a 55 turns of wire around the incoming copper water pipe. It's worth taking time over this and getting the wire coiled neatly and tightly around the pipe to ensure the magnetic field remains concentrated. Half an hour of winding under the kitchen sink and it was ready for testing as shown by the photo below. One tip on fitting the coil, I used cellotape to temporarily keep the wire coil in place, then applied Evo Stick (from a tube) as a more permanent glue. Evo Stick is good because it dries "rubbery" ie is flexible and it can also be removed if necessary. The cellotape is easily removed once the Evo Stick has set (I left it overnight).......

...and note the kit instructions left for future reference!

Results: From my research, I did not expect fast results. In fact I was not entirely sure how to gauge the merits of how well the circuit really did reduce limescale. I opted for three simple tests and one observation:

a) before fitting the descaler, leaving a glass of water overnight tended to result in a scale line at the top of the glass. With the electronic descaler fitted and working, I could not find the usual line of scale. This looks promising.....
b) leaving the washing up to dry overnight also tended to leave limescale marks in the morning, which required some effort to remove (particularly glasses). I did the same thing but with the electronic descaler working, there was very little evidence of limescale the next morning. Positive results again.....
c) clean the taps and see if the limescale returns.....it's been about a week since installation now and I can say the taps and chrome on the waste are looking clear of limescale. (Incidently, to clean the limescale off of the sink and chrome taps only
I used undiluted white vinegar (yep a tip pinched from the TV series "Perfect Housewife", though I don't think I'll achieve that goal!!!!) - seriously, test first as the vinegar will discolour gold and other non chrome taps.
d) Lastly, an observation. In the past I've tried chemical cleaners (anionic cleaners) to remove limescale deposits from eg shower glass. These change the "surface tension" characteristics of the water - put simply, the water does not sit in globules but seems to flow eavenly over the glass surface. With the electronic descaler in use, the same thing happens but without using chemicals. Guess I'll just have to clean the shower door glass (groan, more cleaning......!) and see if the limescale really stays away now the descaler is working.

Conclusion:
I have to admit I was sceptical about the electronic descaler, but after a week, in my humble opinion there is a lot of merit in fitting the descaler especially with a cost under £30. The limescale deposits are visibly reduced, which means I'll be using less chemical cleaners - not only saving money but positive for the environment. It also means less cleaning to do (!).
Again, I would point out the lime is still in the water, but mostly goes harmlessly down the waste pipe. Inevitably a small amount lime sometimes appears on glasses, but I've found it is easily removed just with a wipe of the tea towel.

And lastly, I nearly forgot - just how much electricity does it use?
The circuit takes around 250mA from my 8volt power supply.
That's 2Watts, and I'll conservatively assume my power supply is around 80% efficient, so say 2.5Watts.
2.5Watts amounts to around 60Watt hrs in a day, 420Watt hrs in a week, or 21900 Watt hrs in a year, or 21 kW hrs. Typically, 1kW hr of electricity is around 8 pence so in a year its costs less than £2 to run ......
.... put another way around 4 pence a week which can easily be saved by using less chemical cleaners.
Installed in a new home or new water installation, the real result and savings come by the presumption that the pipes will not get scaled up and hence hot water heaters and kettles will be more efficient.

I hope this article has been of interest and perhaps stimulates some into fitting such a water descaler and I hope the results are as encouraging as mine.
I'm an electronic engineer by profession, and as you may have guessed, I'm also keen on being environmentally friendly so I recycle as much as I can, and try to use as few harmful chemicals as I can around the home.

One very last comment and apologies for being a bit legalistic!!! but please note this article is here for general interest,
and is not endorsed, nor intended to be endorsed by CNTV or The National Trust.